The code for the examples in the chapter is available on GitHub: https://github.com/PacktPublishing/Hands-On-Docker-for-Microservices-with-Python/tree/master/Chapter08.
You will need to install the fluxctl tool. We will then use this tool to sync manually and to obtain an SSH key to allow Flux to interact with the Git repo. See how to install it in its documentation: https://docs.fluxcd.io/en/stable/tutorials/get-started.html.